Di2 Mountain Bike

The Di2 Mountain Bike project was conceived upon considering the following question, “What will the future of mountain biking be?” Internally routed hydraulic and electrical lines, carbon fiber rotors, “single sided forks”, and electric shifting are just some of the possibilities this bike executes. The main focus was to bring together a variety of unique parts in a durable race worthy platform. The build is not necessarily the lightest, but still weighs a feathery 18lbs.The paint scheme was designed by Fairwheel’s Brian Meyer after a discussion involving how to implement Di2 in to a mountain bike platform. Discussion considered the pro’s and con’s of combining a classic panel design with emerging technology and components. The paint lets the carbon tubing emerge amidst classic banding and paneling, while utilizing new color approaches to old designs. The schematics of the seat and top tube cluster are a combination of Di2 elements and circuitry.

The amount of secrecy surrounding the development of Di2 also informed the design. Internet forums had been abuzz with spy photos and speculation. Questions ran the typical gamut asking, “how does it work”, “how will it perform”, “how much will it weigh”, and most humorously – “what if I run out of battery power during a ride?”. How did Fairwheel implement Di2 on a mountain bike? A bit of soldering, a bit of drilling, and a bit of wiring.

A big unknown was just how the bike would perform. After all, mountain biking places unique stresses on a bike. The answer was a relief, with the bike riding and shifting flawlessly, under all of the demands of cross country riding. The project has left us quit certain that we’ll see a MTB specific electric design in the future.

Frame Ruegamer
Fork Use SUB
Rims Edge 26″ XC Clincher
Front Hub Use Sub Hub
Rear Hub Tune Kong
Spokes DT Revolution
Cranks KCNC K-Type XC1 Double Crankset
Chainrings Fibre Lyte carbon fiber.
Chain KMC X10SL
Front Derailleur Shimano Di2 Dura Ace
Rear Derailleur Shimano Di2 Dura Ace
Brakes Magura Disc Brakes
Disc Brake Rotors Fiber-Lyte Carbon
Cassette Shimano Custom 10 Speed 11-32
Skewers KCNC MTB Skewers
Handlebars Edge, Mountain Riser
Grips Extralite Grips
Shifters Custom Electronic Shifters
Saddle Selle Italia
Stem KCNC Stem; Ti Pro
Water Bottle Cages Emporelli Dolomiti Bottle Cage
Seatpost Ax Lightness Europa

14 comments on “Di2 Mountain Bike”

  1. Erich says:

    I am interested in building my own custom made Shifter´s. Do you have any idea obaout the pinout? Is the shifter an active (mcu controlled) part of the system or dumb switches only?
    Any Sources for the plugs?


  2. Ivan says:

    Because of my handicap (lost my right arm) I am interested in the DI2 system on a moutain handlebar (cfr the cory_rosene_di2_mountain_bike_100) . Can you tell me if you can connect the functionbuttons directly to the junction SM-EW79A-E independent the kind of the breakshifters (in others words do you need breakshifters to use the DI2 system?.
    Is it maybe possible to send me the details about how to do this.
    I thank you very much and hope you can give me the solution for my problem.
    Ivan from Belgium.

    1. Ivan, the brake levers are independent of the shifters and the shifter is not a mountain bike shifter at all but it works perfectly. I can’t say too much right now but if you’re interested in upcoming news concerning single shifter Di2 I’d subscribe to our blog updates either by RSS or Email.

  3. sami srour says:

    di2 remote button shifters

  4. @sami srour, The second Di2 Mountain Bike that we did for Interbike 2010 did use the Di2 remote shifters and has since become common for all of our Di2 MTB conversions. This bike was built before those were available and we custom made the shifters.

  5. Pingback: DIY – Di2 |
  6. Alessandro says:

    Here in Italy we can do it 🙂
    1 & 1/2 year off-road test, races, mud, powder, whatever…no problem! Electronic shifting system is the answer. You can have a look on our website! Cheers

  7. Ivan says:

    Hello Allesandro,

    Does the DI2-system also works with another speed cassette, for example the greatest toothwheel with 32 tooths or must it be the standard cassette with maximum 11-27.

  8. Ivan says:


    I see on your website a Mountain Bike with DI2. Can you tell me witch serial numbers of the Shimano parts (SW7970, SW7971, ST7971, ?)you used for changing the gears in font and behind.

    Maybe you can answer on skater007@scarlet.be

    Thank you very much.

  9. Alessandro says:

    Hi Ivan!
    Presently we are riding with: 27-40 Front & 11-34 Rear. For realizing this capability, we modified FD e RD. It’s not so easy, but you can do it. It works really fine! Now we are confident for shifting up to 11-36 (!!): here on my desk I have the Shimano cassette sprocket, I will do it soon 🙂 Then, you are right: SW7970 are the best buttons for managing the system! But, also here you need to modify the connection with consolle system…anyway, I have some pics on our Facebook account http://www.facebook.com/media/set/?set=a.122886834452110.24715.110107649063362&type=3
    Ciao, Alessandro

  10. Jeff says:

    Hi Alessandro,

    Great work. I run a one-by-ten setup on my mountain bike. It’s a 33T chainring up front, and a 10spd 11-36 cassette. If I were doing the di2 conversion only for the rear der, in keeping with the one-by-ten setup, would less modification be necessary since me overall chain wrap is much lower than two-by-ten road/mountain setups?


  11. Alessandro says:

    Jeff, nice idea, 33 mono on the front sounds good! I think you can also manage it in a simple way. Recently I tried to drive only the rear derailleur w/o mounting the front one: it works exept on the led consolle 🙁 so, you wouldn’t have all the electronic features available I guess!
    About the “chain-line”, no doubt everything would be easier and smoother

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